FIG. 5.
Effect of the periplasmic domain on TcpP stability and activity. (A) The ΔtcpP mutant strain was transformed with either tcpPwt (pBAD18) containing the full-length wild-type version of tcpP or tcpPR (pBAD18) containing a chimeric version of tcpP in which the periplasmic domain has been replaced with that of ToxR. Western blot analysis of mid-log cultures was performed after the addition of rifampin to stop transcription. Cultures remained at 30°C after the addition of rifampin through the end of the time course. (B) The same experiment as described for panel A was performed with the ΔtoxR mutant strain transformed with either toxRwt-pBAD18 or toxRP (pBAD18).